Work under this proposal will consist of an examination of parameters of the Edman chemistry reactions that are used in determining the amino acid sequences of proteins. These reactions have constituted the methodology by which the vast majority of known sequences have been accumulated, initially by manual methods but increasingly by automated devices. Both approaches have been advanced through small improvements in the physical and mechanical methods of operation. It now appears that incomplete understanding of the basic chemistry of the reactions and failure to deal with competing reactions have been the limiting factors in perfecting the technique. Present limitations can be overcome by increasing the number of effective cycles performed and by reducing the amount of time required for each cycle. Our recent studies of these reactions, most notably the cleavage reaction, have indicated that considerable improvement can be made in the techniques currently in use, greatly extending the range of the Edman degradation and making it practical to sequence numerous large proteins. In addition to studying the basic chemistry of the sequencing operation, we propose to investigate a variety of sequencing devices capable of employing the improved chemistries and of having a considerably increased through-put. In particular we will develop a continuously operating sequencing-identification instrument that will be computer controlled and thus relieve much of the operator-generated errors and inefficiencies that continue to hamper these procedures. Computer analysis will give the additional benefit of maximizing the information that can be discerned from sequencing data.